Definition - What does Anonymization mean?
Techopedia explains Anonymization
Data anonymization is a technique that will not take away the original field layout (position, size and data type) of the data being anonymized, so the data will still look realistic in test data environments.
One aspect of anonymization that may worry individuals who value their privacy is that the process can be reversed. Many current techniques associated with anonymization can be bypassed as there are ways to reveal stripped personally-identifying information (PII) from datasets. One way this information can be revealed is with cross referencing any sets of records still visible. This is called de-anonymizing.